Signal multi-channel fan-out circuit and test equipment

Abstract

The utility model provides a signal multi-channel fan-out circuit and test equipment, the signal multi-channel fan-out circuit comprises a signal source, a multi-channel fan-out channel, a control module and an acquisition module, and the signal source provides signals required by testing for a plurality of tested devices correspondingly connected through the multi-channel fan-out channel; each fan-out channel comprises an amplitude compensation circuit and a superposition driving circuit; the acquisition module is connected with the superposition drive circuit in each fan-out channel and is used for acquiring signals output by the superposition drive circuits; and the control module is connected with the amplitude compensation circuit in each fan-out channel and is used for controlling the compensation amplitude of the amplitude compensation circuit according to the signal acquired by the acquisition module. According to the invention, accurate adjustment of output signals of the fan-out channels can be realized, and the problem of output signal deviation inconsistency caused by differences of devices, parasitism and the like among the multiple fan-out channels is solved.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuit testing, and particularly to a signal multi-way fan-out circuit and a testing device. Background Art

[0002] In the multi-station parallel testing of some integrated circuits, an automatic testing device is required to provide multiple signal sources, and these multiple signal sources need to output signals with values within a certain range at the same time. These multiple signal sources can be designed as multiple independent and consistent signal sources, and each signal source can be compensated and corrected separately. However, the disadvantage is that the cost is relatively high. These multiple signal sources can also be designed in a way that fans out a single signal source into multiple paths, thereby reducing costs. However, to avoid excessive signal bifurcation, ensure the quality and driving ability of the fanned-out signals, drivers need to be added to each fan-out channel. However, due to factors such as differences in devices and parasitic parameters of PCB traces among each fan-out channel, characteristics such as DC linearity, AC bandwidth, and in-band flatness will be different, which will in turn affect the AC and DC precision and consistency of signals among each fan-out channel.

[0003] Since the above differences will all affect the testing, the method of fanning out a single signal source into multiple paths cannot meet the requirements of multi-station parallel testing either. Summary of the Utility Model

[0004] In view of this, the main purpose of the present application is to provide a signal multi-way fan-out circuit. By adding a compensation circuit to each fan-out channel, precise adjustment of the signals output by the fan-out channels is achieved, and the problem of inconsistent output signal deviations caused by differences in devices, parasitics, etc. among multiple fan-out channels is solved.

[0005] In a first aspect, the present application provides a signal multi-way fan-out circuit, including a signal source, multiple fan-out channels, a control module, and a collection module. The signal source provides signals required for testing for a plurality of devices under test connected correspondingly through the multiple fan-out channels;

[0006] Each fan-out channel includes an amplitude compensation circuit and a superimposed driving circuit. The amplitude compensation circuit is connected to the signal source and is used to perform amplitude compensation on the signal output by the signal source. The superimposed driving circuit is connected to the amplitude compensation circuit and is used to output the amplitude-compensated signal to the device under test connected correspondingly;

[0007] The collection module is respectively connected to the superimposed driving circuits in each fan-out channel and is used to collect the signals output by the superimposed driving circuits;

[0008] The control module is respectively connected to the amplitude compensation circuits in each fan-out channel and is used to control the compensation amplitude of the amplitude compensation circuit according to the signals collected by the collection module.

[0009] As described above, in a signal multi-way fan-out circuit provided by the present application, a signal source is respectively connected to a plurality of devices under test through multi-way fan-out channels, providing signals required for testing for the devices under test, and by setting an amplitude compensation circuit in each fan-out channel, and controlling the compensation amplitude of each fan-out channel through a control module, wherein the amplitude compensation circuit can perform amplitude compensation on the signals output by the signal source, and a superimposed driving circuit connected to the amplitude compensation circuit is also provided in each fan-out channel, which can output the amplitude-compensated signals to the correspondingly connected devices under test. In addition, a collection module is also used to collect the adjusted signals output by the superimposed driving circuit and read them back to the control module, and the control module can achieve precise adjustment of the compensation amplitude according to the collected signals. Through the signal multi-way fan-out circuit provided by the present application, precise adjustment of the signals output by the fan-out channels can be achieved, and the problem of inconsistent output signal deviations caused by differences in devices, parasitics, etc. between multi-way fan-out channels can be solved.

[0010] Optionally, each of the fan-out channels further includes a ground level compensation circuit, which is used to connect the corresponding device under test and the superimposed driving circuit respectively, for compensating the difference between the ground level of the device under test and the ground level of the signal source, and sending the ground level difference compensation to the superimposed driving circuit, so that the superimposed driving circuit superimposes the amplitude-compensated signal and the ground level difference compensation and outputs them to the correspondingly connected device under test.

[0011] As described above, since there may be differences in the ground levels of each work station, there will also be differences in the actual amplitudes of the signals in the fan-out channels at the device-under-test end among work stations. Therefore, the present application also sets a ground level compensation circuit in each fan-out channel, which is respectively connected to the corresponding device under test and the superimposed driving circuit. The ground level compensation circuit can compensate according to the ground level difference between the signal source and the device under test, and send the ground level difference compensation to the superimposed driving circuit, so that the superimposed driving circuit superimposes the amplitude-compensated signal and the ground level difference compensation and outputs them to the correspondingly connected device under test, thereby solving the problem of inconsistent output signal deviations caused by differences in devices, parasitics, etc. and the ground level differences of the devices under test between multi-way fan-out channels.

[0012] Optionally, an output switch is further provided between the superimposed driving circuit and the correspondingly connected device under test, and the on / off of the output switch is controlled by the control module.

[0013] As described above, by setting an output switch between the superimposed driving circuit and the correspondingly connected device under test and controlling it through the control module, switch isolation of the signal to the outside can be achieved.

[0014] Optionally, it further includes an acquisition switch disposed between the superimposed driving circuit and the acquisition module, and the on / off of the acquisition switch is controlled by the control module.

[0015] As described above, by providing an acquisition switch between the superimposed driving circuit and the acquisition module and controlling it through the control module, individual control of each acquisition channel can be achieved.

[0016] Optionally, the amplitude compensation circuit includes a gain control circuit and an operational amplifier circuit. After the gain control circuit performs gain control through the control module, the signal output by the signal source is subjected to gain processing and then input to the operational amplifier circuit, and is output after being processed by the operational amplifier circuit.

[0017] As described above, the amplitude compensation circuit can be composed of a gain control circuit and an operational amplifier circuit, and the gain of the gain control circuit is set through the control module. After the signal output by the signal source is amplified / attenuated by the gain control circuit and then output to the operational amplifier circuit for operation, the amplitude-compensated signal can be output to the superimposed driving circuit.

[0018] Optionally, the gain control circuit includes a variable potentiometer connected to the control module, the operational amplifier circuit includes a first operational amplifier, the variable potentiometer is connected to an input terminal of the first operational amplifier through a switch, the other input terminal of the first operational amplifier is connected to the signal source, and the output terminal of the first operational amplifier is connected to the superimposed driving circuit.

[0019] As described above, the amplitude compensation circuit can be implemented through a variable potentiometer and an operational amplifier. By controlling the variable potentiometer through the control module, the amplification factor of the operational amplifier is adjusted, thereby achieving precise adjustment of the amplitude of the output signal.

[0020] Optionally, the gain control circuit includes a programmable gain amplifier connected to the control module, the operational amplifier circuit includes a second operational amplifier, the input terminal of the programmable gain amplifier is connected to the signal source, the output terminal of the programmable gain amplifier is connected to an input terminal of the second operational amplifier, the other input terminal of the second operational amplifier is connected to its output terminal, and the output terminal of the second operational amplifier is connected to the superimposed driving circuit.

[0021] As described above, the amplitude compensation circuit can be implemented through a programmable gain amplifier and an operational amplifier. By controlling the amplification / attenuation factor of the programmable gain amplifier through the control module, the signal output by the signal source is amplified / attenuated, and further precise adjustment of the amplitude of the signal output by the operational amplifier is achieved.

[0022] Optionally, the ground level compensation circuit includes a third operational amplifier. One input terminal of the third operational amplifier is connected to the ground terminal of the corresponding device under test, and this input terminal is also connected to the reference ground of the signal source through an RC circuit. One input terminal of the third operational amplifier is connected to its output terminal, and the output terminal of the third operational amplifier is connected to the superimposed driving circuit.

[0023] As described above, when performing multi-station testing, the ground levels of different stations may differ from the reference ground of the signal source, which may cause the signal amplitude at the device under test to be inconsistent with the set value. Therefore, an operational amplifier and an RC circuit can be used to perform arithmetic processing on the reference ground of the signal source and the ground terminal of the device under test, compensating for the difference between the ground level of the device under test and the ground level of the signal source, thereby avoiding deviation of the output signal level at the device under test from the set value due to the ground level difference.

[0024] Optionally, the acquisition module includes an ADC sampling circuit, and the ADC sampling circuit is connected to the superimposed driving circuit in each fan-out channel through a bus.

[0025] As described above, the ADC sampling circuit and the bus can be used to sample the signals output by each fan-out channel and provide them to the control module for processing.

[0026] In a second aspect, the present application provides a test device, including a host computer and a signal multi-way fan-out circuit as described above;

[0027] The host computer is respectively connected to the signal source and the control module in the signal multi-way fan-out circuit, and is used for monitoring and controlling the signal source and the control module respectively.

[0028] These and other aspects of the present application will become more clearly understood in the following description of the (multiple) embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a circuit diagram of the first signal multi-way fan-out circuit provided by an embodiment of the present application;

[0030] Figure 2 It is a circuit diagram of the second signal multi-way fan-out circuit provided by an embodiment of the present application;

[0031] Figure 3 It is a schematic diagram of an amplitude compensation circuit provided by an embodiment of the present application;

[0032] Figure 4 It is a circuit diagram of the first amplitude compensation circuit provided by an embodiment of the present application;

[0033] Figure 5 It is a circuit diagram of the second amplitude compensation circuit provided by an embodiment of the present application;

[0034] Figure 6 The circuit diagram of a ground level compensation circuit provided by an embodiment of the present application;

[0035] Figure 7 The circuit diagram of a non-inverting summing operation circuit provided by an embodiment of the present application;

[0036] Figure 8 The circuit diagram of an inverting summing operation circuit provided by an embodiment of the present application;

[0037] Figure 9 The schematic diagram of a signal compensation and calibration process provided by an embodiment of the present application. Specific implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0039] An embodiment of the present application provides a signal multi-way fan-out circuit. By adding a compensation circuit in each fan-out channel, precise adjustment of the output signal of the fan-out channel is achieved, and the problem of inconsistent output signal deviation caused by differences in devices, parasitics, etc. between multiple fan-out channels and the ground level difference of the device under test is solved.

[0040] As Figure 1 shown, an embodiment of the present application provides a first signal multi-way fan-out circuit, including a signal source 100, a multi-way fan-out channel 200, a control module 300, and a collection module 400. The signal source 100 provides signals required for testing for a plurality of devices under test 500 connected correspondingly through the multi-way fan-out channel 200;

[0041] Among them, each fan-out channel 200 includes an amplitude compensation circuit and a superimposed driving circuit. The amplitude compensation circuit is connected to the signal source 100 and is used to perform amplitude compensation on the signal output by the signal source 100. The superimposed driving circuit is connected to the amplitude compensation circuit and is used to output the amplitude-compensated signal to the correspondingly connected device under test 500. The collection module 400 is respectively connected to the superimposed driving circuits in each fan-out channel 200 and is used to collect the signals output by the superimposed driving circuits. The control module 300 is respectively connected to the amplitude compensation circuits in each fan-out channel 200 and is used to control the compensation amplitude of the amplitude compensation circuit according to the signals collected by the collection module 400.

[0042] Based on Figure 1As shown in the figure, in a signal multi-way fan-out circuit provided by an embodiment of the present application, a signal source 100 is respectively connected to a plurality of devices under test 500 through a multi-way fan-out channel 200, provides signals required for testing for the devices under test 500, and by setting an amplitude compensation circuit in each fan-out channel 200, and controlling the compensation amplitude of each fan-out channel 200 through a control module 300, wherein the amplitude compensation circuit can perform amplitude compensation on the signals output by the signal source 100. A superposition driving circuit connected to the amplitude compensation circuit is also provided in each fan-out channel 200, which can output the amplitude-compensated signals to the corresponding devices under test 500. In addition, the acquisition module 400 acquires the adjusted signals output by the superposition driving circuit and reads them back to the control module 300, and the control module 300 can realize precise adjustment of the compensation amplitude according to the acquired signals. Through the embodiment of the present application, precise adjustment of the signals output by the fan-out channels can be realized, and the problem of inconsistent output signal deviations caused by differences in devices, parasitics, etc. between multiple fan-out channels can be solved, thereby improving the test accuracy of the multi-station parallel test of the test equipment.

[0043] As Figure 2 shown in the figure, the second signal multi-way fan-out circuit is further provided in an embodiment of the present application, including a signal source 100, a multi-way fan-out channel 200, a control module 300, and an acquisition module 400. The signal source 100 provides signals required for testing for a plurality of corresponding devices under test 500 through the multi-way fan-out channel 200.

[0044] Among them, each fan-out channel 200 includes an amplitude compensation circuit, a ground level compensation circuit, and a superposition driving circuit. The input end of the amplitude compensation circuit is connected to the signal source 100 and is used to perform amplitude compensation on the signals output by the signal source 100. The input end of the ground level compensation circuit is connected to the corresponding device under test 500 and is used to compensate for the difference between the ground level of the device under test 500 and the ground level of the signal source 100. The superposition driving circuit is respectively connected to the amplitude compensation circuit and the ground level compensation circuit, and is used to superimpose the amplitude-compensated signal and the ground level difference compensation and then output it to the corresponding device under test 500. An output switch is also provided in the connection channel between the superposition driving circuit and the device under test 500, and the on-off control of the output switch is realized through the control module 300 to realize the switch isolation of the signal to the outside. The acquisition module 400 is respectively connected to the superposition driving circuit in each fan-out channel 200 through an acquisition switch and is used to acquire the signals output by the superposition driving circuit. The control module 300 is respectively connected to the amplitude compensation circuit in each fan-out channel 200 and is used to control the compensation amplitude of the amplitude compensation circuit according to the signals acquired by the acquisition module 400.

[0045] In some embodiments, it further includes a host computer 600, which is respectively connected to the signal source 100 and the control module 300, and is used to monitor and control the signal source 100 and the control module 300 respectively.

[0046] As Figure 3 shown, the amplitude compensation circuit provided by the embodiment of the present application can be implemented by a gain control circuit and an operational amplifier circuit. After the gain control circuit performs gain control through the control module 300, the signal output by the signal source 100 is amplified / attenuated and then output to the operational amplifier circuit for operation, and the amplitude-compensated signal is output to the superimposed driving circuit through the operational amplifier circuit.

[0047] In the first embodiment, the amplitude compensation circuit of the present application can be implemented by an adjustable potentiometer and an operational amplifier, where the adjustable potentiometer can be a digital adjustable potentiometer or a mechanical adjustable potentiometer. As Figure 4 shown in the first amplitude compensation circuit, it includes a digital adjustable potentiometer R4 and an operational amplifier N1. The digital adjustable potentiometer R4 is connected to an input terminal of the operational amplifier N1 through a switch KC1. An input terminal of the operational amplifier N1 is also connected to its output terminal through a resistor R3. The other input terminal of the operational amplifier N1 is connected to the output terminal of the signal source 100 through a resistor R1. The other input terminal of the operational amplifier N1 is also grounded through a resistor R2. The output terminal of the operational amplifier N1 is used as the output terminal of the amplitude compensation circuit and is connected to the subsequent superimposed driving circuit. The digital adjustable potentiometer R4 of this embodiment is also connected to the control module 300, and its resistance value is adjusted through the control module 300 to adjust the amplification factor of the operational amplifier N1, so as to realize the precise adjustment of the amplitude of the output signal.

[0048] Next, based on Figure 2 the signal multiplexing fan-out circuit shown and Figure 4 the amplitude compensation circuit shown, the amplitude compensation process will be described in detail. Refer to Figure 4 , disconnect the switch KC1. Refer to Figure 2 , set the signal source 100 to output a DC voltage of V through the host computer 600. Close the output switch K11 and the acquisition switch K12 in Figure 2 , select the voltage of the output terminal OUT1 of the fan-out channel to the internal bus, and control the acquisition module 400 to sample the voltage of the output terminal OUT1 through the control module 300 to obtain the voltage V1 of the output terminal OUT1, calculate the proportional coefficient k = V / V1, according to Figure 4The resistance values of the required digitally adjustable potentiometer R4, i.e., R4', are calculated based on the resistors R1, R2, and R3 in it. Then, the control module 300 is used to set the resistance value of the digitally adjustable potentiometer R4 to R4', and the switch KC1 is closed. At this time, the voltage at the output terminal OUT1 can be accurately adjusted to the set value V. The R4 values of other fan-out channels are adjusted in the same way, so that the output values of multiple fan-out channels can be adjusted to the set value V, thus ensuring the consistency of the output voltages among the fan-out channels.

[0049] In the second embodiment, the amplitude compensation circuit of the present application can also be implemented by a programmable gain amplifier VGA and an operational amplifier. As Figure 5 shown in the second amplitude compensation circuit, it includes a programmable gain amplifier VGA and an operational amplifier N2. The input terminal of the programmable gain amplifier VGA is connected to the output terminal of the signal source 100. The output terminal of the programmable gain amplifier VGA is connected to one input terminal of the operational amplifier N2. The other input terminal of the operational amplifier N2 is connected to its output terminal (the other input terminal of the operational amplifier N2 can also be connected to its output terminal through a resistor R5). The output terminal of the operational amplifier N2 serves as the output terminal of the amplitude compensation circuit and is connected to the subsequent superposition driving circuit. The programmable gain amplifier VGA of this embodiment is also connected to the control module 300, and the amplification / attenuation multiple is adjusted through the control module 300, thereby achieving precise adjustment of the amplitude of the output signal of the operational amplifier N2.

[0050] When performing multi-station tests, the ground levels of different stations may be different from the reference ground of the signal source, which may cause the signal amplitude at the device under test to be inconsistent with the set value. Therefore, it is necessary to compensate for the difference between the ground level of the device under test and the reference ground of the signal source. As Figure 6 shown, a ground level compensation circuit provided by an embodiment of the present application can be implemented by an operational amplifier N4 and an RC circuit. One input terminal of the operational amplifier N4 is connected to the grounding terminal DGS of the corresponding device under test. This input terminal is also connected to the reference ground GND of the signal source through an RC circuit composed of a capacitor C1 and a resistor R6. The other input terminal of the operational amplifier N4 is connected to its output terminal (the other input terminal of the operational amplifier N4 can also be connected to its output terminal through a resistor R7). The output terminal of the operational amplifier N4 serves as the output terminal of the ground level compensation circuit and is connected to the subsequent superposition driving circuit. The operational amplifier N4 performs arithmetic processing on the reference ground of the signal source and the ground level of the device under test, compensating for the difference between the ground level of the device under test and the ground level of the signal source, thereby avoiding deviation of the level of the output signal at the device under test from the set value due to the difference in ground levels.

[0051] Based on Figure 6The shown ground - level compensation circuit, when there is a level difference between the ground level Vdgs of the device under test and the signal - source reference ground Vgnd, denoted as ΔVgnd = Vdgs - Vgnd, after being followed by the operational amplifier N4, the output is ΔV, which is used as the output of the ground - level compensation circuit and is output to the subsequent superposition driving circuit. The superposition driving circuit superimposes the ground - level difference ΔV and the output signal Vsig of the amplitude compensation circuit, and the superimposed output is Vsig+ΔV. This ensures that the potential difference of the signal Vsig + ΔV relative to the ground level Vdgs of the device under test at the device - under - test end is Vsig + ΔV - Vdgs = Vsig - Vgnd, which is consistent with the set value Vsig of the signal source, thereby avoiding the deviation of the output signal level from the set value at the device - under - test end due to the ground - level difference.

[0052] In some embodiments, the above - mentioned ground - level compensation circuit is further provided with a plurality of diodes D1, D2 connected in parallel with the RC circuit. These diodes can be used to limit the potential difference between the ground level of the device under test and the ground level of the signal source, and the number of these diodes can be adjusted according to the allowed potential difference.

[0053] The superposition driving circuit of the embodiment of the present application can be respectively connected to the above - mentioned amplitude compensation circuit and ground - level compensation circuit, and is used to superimpose the amplitude - compensated signal and the ground - level difference compensation and then output to the corresponding device under test. Among them, the superposition driving circuit can be realized by an in - phase summing operation circuit or an anti - phase summing operation circuit composed of an operational amplifier and a plurality of resistors. Since the in - phase summing operation circuit has a high input impedance and the anti - phase summing operation circuit has a low input impedance, the in - phase summing operation circuit or the anti - phase summing operation circuit can be selected according to the input impedance of the signal to realize the superimposed output of the amplitude - compensated signal and the ground - level difference compensation.

[0054] As Figure 7 shown, the embodiment of the present application provides an in - phase summing operation circuit. The in - phase summing operation circuit includes an operational amplifier N00. The non - inverting input terminal of the operational amplifier N00 is respectively connected to the output terminals of the above - mentioned amplitude compensation circuit and ground - level compensation circuit through resistors R00 and R01. The non - inverting input terminal is also grounded through a resistor R02. The inverting input terminal of the operational amplifier N00 is grounded through a resistor R03. A resistor R04 is connected between the inverting input terminal and the output terminal, and the output terminal is connected to the corresponding device under test, and is used to superimpose the amplitude - compensated signal and the ground - level difference compensation and then output to the corresponding device under test.

[0055] As Figure 8As shown in the figure, an embodiment of the present application provides an inverting summing operation circuit. The inverting summing operation circuit includes an operational amplifier N01. After the inverting input terminal of the operational amplifier N01 is connected to an inverter (not shown), it is respectively connected to the output terminals of the above-mentioned amplitude compensation circuit and ground level compensation circuit through resistors R06 and R07. A resistor R08 is connected between the inverting input terminal and the output terminal. The non-inverting input terminal of the operational amplifier N01 is grounded, and the output terminal is connected to the corresponding device under test, and is used to output the amplitude-compensated signal and the ground level difference-compensated signal after superposition to the corresponding device under test.

[0056] Alternatively, in other implementation manners, the inverting input terminal of the operational amplifier N01 is respectively connected to the output terminals of the above-mentioned amplitude compensation circuit and ground level compensation circuit through resistors R06 and R07. A resistor R08 is connected between the inverting input terminal and the output terminal. The non-inverting input terminal of the operational amplifier N01 is grounded, and the output terminal is connected to an inverter (not shown) and then connected to the corresponding device under test.

[0057] In some embodiments, the acquisition module 400 of the present application can be implemented by an ADC sampling circuit. The ADC sampling circuit is connected to the superimposed driving circuit in each fan-out channel through a bus, samples the signals output by each fan-out channel, and provides them to the control module 300 for processing. The control module 300 can be an independent controller or a controller shared with the signal source. The controller can be a microprocessor MCU or a programmable logic controller FPGA. Through this controller, control such as compensation of the amplitude compensation circuit, on / off of the output switch, ADC data acquisition and readback can be realized.

[0058] In some embodiments, a calibration device can also be used to adjust the compensation amplitude in multiple fan-out channels. Based on the following Figure 9 schematic diagram of the signal compensation calibration process and the Figure 4 amplitude compensation circuit shown, the amplitude compensation process will be described in detail. As Figure 9 shown, the input terminals of the calibration device are respectively connected to the output terminals of the superimposed driving circuits in each fan-out channel, and are used to collect the output signals of each superimposed driving circuit. The grounding terminals of the calibration device are respectively connected to the input terminals of the ground level compensation circuits in each fan-out channel, and are used to provide a reference ground level signal to each ground level compensation circuit. Referring to Figure 4 and Figure 9 shown, the signal compensation calibration process is as follows:

[0059] Refer to Figure 4 , disconnect the switch KC1, refer to Figure 9, a host computer 600 is used to set the signal source to output a set of DC voltage values (Vset1, Vset2... Vsetm). At the same time, the calibration device is controlled to measure the actual voltage values output by each fan-out channel. For example, the measured values of fan-out channel 1 are recorded as (VO1act1, VO1act2... VO1actm), and the measured values of fan-out channel n are recorded as (VOnact1, VOnact2... VOnactm). By fitting the set values output by the signal source and the measured values of each fan-out channel, the mathematical relationship expression between the output values and the set values of each fan-out channel can be obtained, and each coefficient of the expression is stored in the host computer or the control module for subsequent calculations. This process is called calibration and can be implemented regularly.

[0060] Assume that a linear fit is performed on the set values and the measured values of each fan-out channel, and the following relationship expression can be obtained:

[0061] VO1 = k1 * Vset + b1; (1)

[0062] …

[0063] VOn = kn * Vset + bn; (n)

[0064] The coefficients k1, b1... kn, bn of each fan-out channel are stored in the non-volatile memory in the host computer or the control module. When the signal source is set to output a DC voltage V, the control module can calculate the proportional coefficient k = VO1 / V = k1 + b1 / V of fan-out channel 1 according to formula (1). According to Figure 4 the resistances R1, R2, R3 in the amplitude compensation circuit shown, the resistance value R4' of the required digitally adjustable potentiometer R4 is calculated, and then the control module sets the resistance value of the digitally adjustable potentiometer R4 to R4', and closes the switch KC1. At this time, the voltage at the output terminal OUT1 can be accurately adjusted to the set value V. The R4 value of other fan-out channels is adjusted in the same way, so that the output values of multiple fan-out channels can be adjusted to the set value V, thus ensuring the consistency of the output voltages between each fan-out channel.

[0065] It should be noted that the above is the compensation process for DC voltage. For AC signals, their output amplitude is also related to the frequency, and the signal amplitude characteristics at different frequencies are inconsistent. Therefore, it is necessary to compensate the AC signals at different frequencies to obtain different amplitude-frequency compensation coefficients. The process of calibration and compensation is the same as above and will not be elaborated here.

[0066] Adopting this compensation and calibration method in this embodiment, it is not necessary to actually test the voltages at the output terminals OUT1... OUTn of each fan-out channel every time. The amplitude of the signal input to the signal source can be directly compensated according to the stored coefficients, improving the calibration and compensation efficiency of the output signals of each fan-out channel.

[0067] In summary, in a signal multi-way fan-out circuit provided by an embodiment of the present application, a signal source is respectively connected to a plurality of devices under test through multi-way fan-out channels, provides signals required for testing for the devices under test, and sets an amplitude compensation circuit and a ground level compensation circuit in each fan-out channel, and controls the compensation amplitude of each fan-out channel through a control module. The amplitude compensation circuit can compensate the amplitude of the signal output by the signal source, and the ground level compensation circuit can compensate according to the ground level difference between the signal source and the device under test. A superimposed driving circuit connecting the amplitude compensation circuit and the ground level compensation circuit is also arranged in each fan-out channel, which can superimpose the amplitude-compensated signal and the ground level difference compensation and output it to the correspondingly connected device under test. In addition, a collection module is used to collect the adjusted signal output by the superimposed driving circuit and read it back to the control module, and the control module can achieve precise adjustment of the compensation amplitude according to the collected signal. Through the signal multi-way fan-out circuit provided by the present application, precise adjustment of the output signal of the fan-out channel can be realized, and the problem of inconsistent output signal deviation caused by differences in devices, parasitics, etc. between multi-way fan-out channels and the ground level difference of the device under test can be solved, thereby improving the test accuracy of the multi-station parallel test of the test equipment.

[0068] An embodiment of the present application also provides a test equipment, which includes a host computer and the signal multi-way fan-out circuit in any of the above embodiments. The host computer is respectively connected to the signal source and the control module in the signal multi-way fan-out circuit, and is used to monitor and control the signal source and the control module respectively, and perform parallel tests on multi-station devices under test. The test equipment of this embodiment can realize precise adjustment of the output signal of the fan-out channel, solve the problem of inconsistent output signal deviation caused by differences in devices, parasitics, etc. between multi-way fan-out channels, thereby improving the test accuracy of the multi-station parallel test of the test equipment.

[0069] It should be noted that the embodiments described in the present application are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and illustrated in the drawings can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0070] The words "first, second, third", etc. in the specification and claims are only used to distinguish similar objects, and do not represent a specific order for the objects. It can be understood that, under the condition of permission, the specific order or sequence can be interchanged so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0071] In the above description, the reference numerals indicating steps do not necessarily mean that the steps will be executed in this order. It may also include intermediate steps or be replaced by other steps. Where permitted, the order of the front and rear steps may be interchanged, or the steps may be executed simultaneously.

[0072] The term "comprising" used in the specification and claims should not be construed as being limited to the content listed thereafter; it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the stated features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps or components and their groups. Thus, the expression "a device comprising device A and B" should not be limited to a device consisting only of components A and B.

[0073] The "one embodiment" or "embodiment" mentioned in this specification means that the specific features, structures or characteristics described in connection with that embodiment are included in at least one embodiment of the present application. Therefore, the phrases "in one embodiment" or "in an embodiment" that appear throughout this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. In addition, in the various embodiments of the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0074] Note that the above is only the preferred embodiment of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, more other equivalent embodiments can be included, all of which fall within the protection scope of the present application.

Claims

1. A signal multi-way fan-out circuit, characterized in that It includes a signal source, multiple fan-out channels, a control module, and an acquisition module. The signal source provides signals required for testing to a plurality of devices under test connected correspondingly through the multiple fan-out channels. Each fan-out channel includes an amplitude compensation circuit and a superimposed driving circuit. The amplitude compensation circuit is connected to the signal source and is used to perform amplitude compensation on the signals output by the signal source. The superimposed driving circuit is connected to the amplitude compensation circuit and is used to output the amplitude-compensated signals to the devices under test connected correspondingly. The acquisition module is respectively connected to the superimposed driving circuits in each fan-out channel and is used to acquire the signals output by the superimposed driving circuits. The control module is respectively connected to the amplitude compensation circuits in each fan-out channel and is used to control the compensation amplitude of the amplitude compensation circuits according to the signals acquired by the acquisition module.

2. The circuit according to claim 1, wherein Each fan-out channel further includes a ground level compensation circuit, which is used to be respectively connected to the corresponding devices under test and the superimposed driving circuit, to perform differential compensation on the ground level of the devices under test and the ground level of the signal source, and send the ground level differential compensation to the superimposed driving circuit, so that the superimposed driving circuit superimposes the amplitude-compensated signals and the ground level differential compensation and then outputs them to the devices under test connected correspondingly.

3. The circuit according to claim 1, wherein It further includes an output switch disposed between the superimposed driving circuit and the device under test connected correspondingly, and the on / off of this output switch is controlled by the control module.

4. The circuit according to claim 1, characterized in that, It further includes an acquisition switch disposed between the superimposed driving circuit and the acquisition module, and the on / off of this acquisition switch is controlled by the control module.

5. The circuit according to claim 1, characterized in that, The amplitude compensation circuit includes a gain control circuit and an operational amplifier circuit. After the gain of the gain control circuit is controlled by the control module, it performs gain processing on the signals output by the signal source and then inputs them to the operational amplifier circuit, and outputs them after being processed by the operation of this operational amplifier circuit.

6. The circuit according to claim 5, wherein The gain control circuit includes a variable potentiometer connected to the control module. The operational amplifier circuit includes a first operational amplifier. The variable potentiometer is connected to an input terminal of the first operational amplifier through a switch. The other input terminal of the first operational amplifier is connected to the signal source, and the output terminal of the first operational amplifier is connected to the superimposed driving circuit.

7. The circuit according to claim 5, characterized in that, The gain control circuit includes a programmable gain amplifier connected to the control module. The operational amplifier circuit includes a second operational amplifier. The input terminal of the programmable gain amplifier is connected to the signal source. The output terminal of the programmable gain amplifier is connected to an input terminal of the second operational amplifier. The other input terminal of the second operational amplifier is connected to its output terminal. The output terminal of the second operational amplifier is connected to the superimposed driving circuit.

8. The circuit according to claim 2, characterized in that, The ground level compensation circuit includes a third operational amplifier. One input terminal of this third operational amplifier is connected to the grounding terminal of the corresponding device under test. This input terminal is also connected to the reference ground of the signal source through an RC circuit. One input terminal of the third operational amplifier is connected to its output terminal. The output terminal of the third operational amplifier is connected to the superimposed driving circuit.

9. The circuit according to claim 1, wherein The acquisition module includes an ADC sampling circuit, and the ADC sampling circuit is connected to the superposition driving circuit in each fan-out channel through a bus.

10. A testing device, characterized in that, It includes a host computer and a signal multi-fan-out circuit according to any one of claims 1 to 9; The host computer is respectively connected to the signal source and the control module in the signal multi-fan-out circuit, and is used to monitor and control the signal source and the control module respectively.

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